The work reported in this dissertation was done in collaboration with Henrik Dam at the Biochemical Institute of the University of Copenhagen and concerns the biologic action and standardization of the new antihemorrhagic vitamin K. At present the only species in which this substance is known to be necessary for life is the chicken. Avitaminosis K is marked by hemorrhages in various parts of the body, especially the breast, legs, gizzard and liver. The coagulation time is strikingly prolonged, and the bleeding results finally in anemia; but the author presents evidence that the hemorrhagic diathesis is not comparable to hemophilia in man and that the anemia is secondary to the hemorrhages.
The substance which prevents or cures this state, as the case may be, is a fat-soluble, nonsaponifiable, thermostable material which is not a sterol and which is not identical with any previously known vitamin. It is found in hempseed,